The present invention is directed to a strapping machine chute opening system. More particularly, the present invention is directed to a strapping machine having a chute opening system that automatically opens the strap chute upon opening the work surface or table top of the machine.
Strapping machines are well known in the art for securing straps around loads. One type of known strapper is a stationary unit that includes a strapping head or weld head and drive mechanism mounted within a frame. A chute is mounted to the frame, through which the strapping material is fed. In a typical arrangement, a table-top or work surface is likewise mounted to the frame.
In a typical stationary strapper, the chute is mounted from about the work surface, and the strapping head is mounted below the work surface. Strap is fed (by a feed system) from a source or dispenser through the strapping head and chute and back to the strapping head, to pull the strap from the chute to around the load and to tension the strap around the load.
In the event a strap error occurs, the faulted strap is ejected from the strapping machine by the feed system. Typically, this process is carried out automatically to reduce operation time and attention. However, there are times that an operator must access the area below the work surface and times at which the operator must open the bottom leg of the chute (adjacent to the strapping head) in order to, for example, clear strap from the chute.
One known arrangement that provides both a work surface support function and a chute opening function uses a long, cantilevered arm with a spring that pivots upwardly to assist the opening function. The system is configured such that the spring is substantially tensioned when the work surface is in the down or operating position.
One drawback to this arrangement is that a “lighter” work surface is more likely to pivot slightly open which in turn isolates power to the strapper (through a keyed interlock). Moreover, if the work surface is replaced, it must be replaced with a surface of similar weight and configuration. In addition, because the spring is at tension when the work surface is open, the spring might not be able to provide sufficient force to then open the chute.
Accordingly, there is a need for a strapping machine having an automatic chute opening system. Desirably, such a system uses a cam surface to leverage the opening of the work surface for opening the chute.